Modal window for a computer display screen



FIG. 1 is a front view of a modal window for a computer display screen; and,

FIG. 2 is a front view of a second embodiment thereof.

The broken line drawing of the outline of a window in both figure views if for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a modal window for a computer display screen, as shown and described. 